Fabrication of MnO2TiO2 nanotube arrays composite films through a one-step redox precipitation method

The MnO2TiO2 nanotube arrays composite films were prepared through depositing MnO2 into TiO2 nanotube arrays by a one-step redox-precipitation method. Morphologies, crystal structure, chemical composition, and supercapacitor performances of the samples were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical analysis. The effects of preparation conditions on the capacitance performance of MnO2TiO2 nanotube arrays composite films were studied. Results show that the composite films were composed of bamboo-like tubes with MnO2 nanoparticles being deposited onto the tube walls and the combination of MnO2 significantly improved the capacitance values of the samples. The temperature of KMnO4 solution, the concentration of MnSO4 and the calcination temperature of the samples have significant influence on their capacitance performance. When the concentration of MnSO4 solution was 0.2 mol/L, the reaction temperature was 50 °C and the annealing temperature was 100 °C, the capacitance value of the samples was 31.11 mF/cm2 at a current density of 1.0 μA/cm2 and the capacitance retention was 85.31% after 1000 cycles.